Locomotive arch



3 10, 3 J. C.'CHAPPLE 1,857,272

LOCOMOTIVE ARCH Filed Nov.5, 1928 2 Sheets-Sheet J.

124' ATTORNEY Patented May 10, 1932 JOHN CHAPIPLE, OF ST. LOUIS, MISSOURI rocono'rrvn Anon Application filed November 5, 1928. ,Serial No. 317,203.

This invention relates to improvements in locomotive arches, and more'particularly. to a simple and novelform or construction of the arch brick or unit.

It is the primary'obj ect and purpose of my in present invention to provide an arch brick or unit of such construction that the same may be readily mounted'a-nd arranged between spaced supporting elements of the firebox structure, and will offer maximum and uniform resistance throughout that portion of the brick which is subjected to the greatest deteriorating effects of the intenseheat of the combustion chamber and the abrasive action of particles of coal and ash.

It is common practice to provide inclined water tubes in a locomotive firebox extending from the lower portion of the flue sheet of the combustion chamber rearwardly and upwardly to the rear firebox sheet for the pure pose'of circulating the water and expediting and increasing steam production. I In some instances it is also the practice to provide other water evaporatingv surfaces such as siphons for this purpose. It has likewise been common practice to arrange and support refractory bricks or units onv the inclined water tubes, the siphons and side sheets of. they fire box either directly, or indirectly by thecprovision of suitable supporting lugs ortrunnions fixed to the siphonsor side sheets to thereby provide a bafiie between the upper portion of the combustion chamber and the lower portion of the firebox where combustion is initiated and'the flue sheet. These refractory bricks or units have been madein various shapes, the 7 present most favored forms being either flat with all parts, of the brick positioned in a commonplane, or one having a concave-convex; form with curved upper and lower surfaces and variously shaped ends to seat upon the tubes or other supports. Brick of the latter type, as now made have their greatestthickness at the center line of the brick and gradually decrease in thickness from the brick center 'to-oppo-H site edges thereof. In-the practical'use of such "brick, it hasbeen found that the de;

teriora-ting eflect of the intense combustion chamber temperature and the abrasive action of 'coal and ash particles on theibrick is just as severe at certain otherportionsas it is at the center of the brick so that such brick rapidly wear away and it is necessary to replace the same by new brick with more or less frequency.

It is the important feature of my, invention to provide anarch brick construction whereby this condition is remedied, the use ful life of the brick materially increased, and replacement thereof by new brick necessitated only after a comparatively prolonged period of useful service. To this end, in a preferred embodiment of the invention, the

V baffle brick is of general arch shape form, the

upper and lower surfaces thereof beingconcentrically curved from radii on the center line of the brick and such surfaces extend ing over themajor portion of one dimension of the brick on opposite sides of said center line solthat such portion of the brick will have a uniform predetermined thickness. The upper surface of the brick at its-opposite edges extends from shorter radii at each side of the center line of the brick and at a tangent to the intermediate upper curved surface of the brick. Thus, these opposite edge portions of the brick which rest or seat upon the spaced supporting elements'of the fire box structure containless refractory material or are relatively thin, since at these, edge portions of the brick the effects of excessive temperatures and of abrasive action are less severe. vThis construction likewise permits heatingof the brick to a morenearly uniform degree in all parts thereof, thereby obviating physical strains due to uneven expansion and varying conditions of use. I

Having above briefly described the principal objects and purposes of my invention, reference may now be had to the accompanying drawings, wherein I have illustrated severalidesirable practical embodiments,and to the following, description wherein these ilr Fig. 3 is a similar sectional view showing the side bricksupported in a horizontal position with its outer end resting upon a lug or trunnion fixed to the sidesheet;

Fig. t is an'enlarged top plan View showing one of the center brick arranged between spaced water tubes; 1

Fig. 5 is an enlarged edge view of one of the center brick diagrammatically indicating the different radii for the differently curved upper surface sections of the brick;

Fig. 6 is an enlarged fragmentary view illustrating the construction of the outer edge of one of the side brick when mounted or supported upon a lug or trunnion fixed to the side sheet;

; Fig. 7 is a similar detail view illustrating an: alternative form which is applicable to either the centeror side-brick; J r i Fig. 8 is a view similar to Fig. 5 showing a center brick having one edge thereof pro-' vided with spacedsurfaces for contact with the water tube, .and

i Fig. 9 is an enlarged detail view of the side or wing brick shown in Fig. 2. V In Fig. .l'of the drawings, for purposes of illustration I have generally indicated a locomotive firebox 1 having side sheets 2, a fluefs'heet'3 and arearsheet 4 This firebox is provided in the usual manner with a pluralit'y ofwwater circulating tubes extending longitudinally thereof insubstantially parallel relation'to each other. In practice, these tubes are usually vertically inclined and extend from the lower part of the flue sheet 3 to therupper part of the rear sheet 4 to aid i the rapid circulation of the'water in its conversion into steam. The tubes designated 5 are usually referred to as the side tubes, while the tubes 6 are the intermediate orcenter,

tubes. v V I i As hereinshown the refractory arch extends from the flue sheet 3:rearwardly to a point in suitably spaced relation from the rear sheett and is supported upon-and between the tubes 5 and 6 and the side sheets 2 of thefirebox. Thisarch is composed of a plurality of individual refractory bricks or units, of which two form's-are used. Thus the centeror intermediate arch brick '4' which.

rest upon and are supported by the tubes 5 and 6 may be provided on opposite edges with arcuately curved seating surfaces 8 for engagement upon the water circulating tubes, or these opposite edges of the baffle brick may each be provided with the two convex surface portions 9 providing for spaced points of contactupon the water tubes. This form is particularly advantageous when used as a sidebrick supported on trunnions and the outertubesin thoseinstances where the distance between the outer side tub-es 5 and the side sheets 2 of the firebox varies from one end to the other ofthe arch. It will also be understood that such spaced contact surfaces 9 may also be provided upon one edge of the side brick of; the arch which are. indicated atlO.

The side brick iotssmwnm Figs. 2 and 9 of the drawings, are provided along one edge with the concaveseating surface 11 to engage on the tube'5, while the opposite edge of the brick is curved reversely to the intermediate portion thereof'to be presently described in detail as indicated at 12, thereby providing a convex bearing surface 13 for Contact against the side sheet 2 and permitting these side brick td'automatically accommodate themselves to'variations in the space between the side tubes 5 and the firebox side sheets 2. In some instances, it is desirable to haveall of the brick constituting the arch wall positioned in a "common horizontal plane, and in such cases, instead of providing the side brick with the curved edge portions 12, I may provide the underside 'of each of these brick at one edge thereof with either a flat or slightly concaved seat indicated at 14 to rest upon the lug or trunnion indicated at 15 which. is'welded'or otherwise permanently fixed to the side sheet 2. V

a I may alsoprovide the center brick of the arch at their opposite-edges with the lower convex surfaces'16 merging into the interme diate concave lower surface ofxthe brick to rest upon'the. surfaces of the spaced water tube s. Suchco'nvex surfaces onthe edges of-the brick as shown 'in either Figs. 7 or 8 are ofadvantage when theisizeof the arch tubes vary or when they. may be. somewhat out of alignment. i a Referring now to Fig. 5 of the drawings it will be understood that-theI fOIIOwing de scription applies equally'well to both the center andthe side brick, and it will be noted that the lower surface 17 of the brick extends I in a continuous concave are between the opposite'edge surfaces which seat or rest 11 on the spaced supportingelements ofthe rebox structure. Assuming'that this arcuate lower surface of-the brick has a center at A, the upper surface 18 of the brick extends in a parallel ;arcffrom the same center and for the major part of the distance between the center' line offthe bri'ckand the opposite edges thereof. Thereore, that part of the brickwhich are seated upon the supportingelements describe different convex arcs as indicated at 19 from the shorter radii C at either side of the center line of the brick. These edge sections 19 of the upper surface of the brick are curved on lines which are tangent to the intermediate section 18 ofsaid' surface and merge into the latter. .As will be apparent, these edge portions 19 of the upper surface of the brick extend from the intermediate section 18 of said surface in non-parallel convergent relation with the extended arc of the lower. surface 17 of the brick. Thus from the lines B, the edge portions of the brick adjacent to the supporting elements of the firebox structure gradually decrease in thickness relative to the major intermediate part of the brick structure.

With reference to the side brick of the arch shown in Figs. 2 and 9 of the drawings, it will be understood that the upper surface of the edge portion 12 of the brick extends from the intermediate upper surface section 18 in a reverse are, or is concave instead of convex,

said concave arcuate surface having its center.

at a point above a line connecting the center of the water tube with the point of engage-' ment of the convex edge face 13 of the brick with the side sheet 2 of the firebox.

From the foregoing description considered in connection with the accompanying drawings, it is believed that the several novel features of my new arch brick construction as well as the advantages thereof in practical use willbe readily understood. By reason of such improvements, I have succeeded in materially increasing the period of serviceability of such arch brick before replacement is required. At the same time, it is evident that such improvements readily lend themselves to quantity production of the arch brick on a large scale without appreciable increase in manufacturing cost. 1

While I have herein shown and described several simple and practical forms of my present improvements, it is nevertheless to be understood'that the'essential features thereof are also capable of embodiment in various other alternative structures, and I accordingly reserve the privilege of'resorting to all such detail changes'therein as may be fairly embodied within the spirit and scope of the invention as claimed. 7 I

I claim: 1. A refractory arch brick having opposite edge portions provided with means for engagement upon spaced supporting elements of a firebox structure, said brick being arched between said edge portions and having an upper convex surface extending between said edge port-ions in substantially concentric relation with the lower concave surface of the brick to provide central and intermediate sections of the brick structure of substantially uniform thickness, and the up er surfaces of said edge portions of the bric being curved on relatively short arcs merging into the remaining upper surface of the brick and in convergent relation to the lower concave sur-,

face of the brick to thereby provide continuations of the brick arch constituting edge portions on the brick of gradually decreasing thickness for contactwith the spaced supporting elements. 1

2. A refractory arch brick for firebox baffle walls adapted to be supported upon and between spaced elements of the firebox structure, said arch brick having an edge portion formed to provide a plurality of inwardl converging convex surfaces for contact wit one of the suporting elements which extend continuously throughout one dimension of the brick.

8. A refractory arch'brick for firebox bafile walls adapted to be supported upon and between spaced elements of the firebox structure, said arch brick having an edge portion provided witha plurality of convex surfaces of unbroken continuity throughout one dimension of the brick, one or all of which are adapted to contact upon one of the supporting elements.

In testimony that I claim the foregoing as JOHN CHAPPLE. 

